We have investigated the effects of the methylammonium bromide (MABr) content of the precursor solution on the properties of wide-bandgap methylammonium lead tribromide (MAPbBr
) perovskite solar ...cells (PSCs). In addition, the anti-solvent process for fabricating MAPbBr
perovskite thin films was optimized. The MAPbBr
precursor was prepared by dissolving MABr and lead bromide (PbBr
) in N,N-dimethylformamide and N,N-dimethyl sulfoxide. Chlorobenzene (CB) was used as the anti-solvent. We found that both the morphology of the MAPbBr
layer and the PSCs performance are significantly affected by the MABr content in perovskite precursor solution and anti-solvent dripping time. The best-performing device was obtained when the molar ratio of MABr:PbBr
was 1:1 and the CB drip time was 10 s. The best device exhibited a power conversion efficiency of 7.58%, short-circuit current density of 7.32 mA·cm
, open-circuit voltage of 1.30 V, and fill factor of 79.87%.
Perovskite solar cells (PSCs) have been significantly improved by utilizing an inorganic hole-transporting layer (HTL), such as nickel oxide. Despite the promising properties, there are still ...limitations due to defects. Recently, research on self-assembled monolayers (SAMs) is being actively conducted, which shows promise in reducing defects and enhancing device performance. In this study, we successfully engineered a p-i-n perovskite solar cell structure utilizing HC-A1 and HC-A4 molecules. These SAM molecules were found to enhance the grain morphology and uniformity of the perovskite film, which are critical factors in determining optical properties and device performance. Notably, HC-A4 demonstrated superior performance due to its distinct hydrophilic properties with a contact angle of 50.3°, attributable to its unique functional groups. Overall, the HC-A4-applied film exhibited efficient carrier extraction properties, attaining a carrier lifetime of 117.33 ns. Furthermore, HC-A4 contributed to superior device performance, achieving the highest device efficiency of 20% and demonstrating outstanding thermal stability over 300 h.
A Nickel oxide (NiOx) thin films were prepared via sol-gel process on a transparent conductive oxide glass substrate. The NiOx thin films were spin-coated in ambient air and subsequently annealed for ...30 minutes at temperatures ranging from 150℃ to 450℃. The structural and optical characteristics of the NiOx thin films annealed at various temperatures were measured using X-ray diffraction, field emission scanning electron microscopy, and ultraviolet-visible spectroscopy. After optimizing the NiOx coating conditions, perovskite solar cells were fabricated with p-i-n inverted structure, and its photovoltaic performance was evaluated. NiOx thin films annealed at 350℃ exhibited the most favorable characteristics as a hole transport layer, resulting in the highest power conversion efficiency of 17.88 % when fabricating inverted perovskite solar cells using this film.
Cu(In,Ga)Se
2
(CIGSe) has been proven to be a better candidate as a light absorber layer in thin-film solar cells. However, most processes require high vacuum and high temperature during deposition, ...which results in significant loss of materials and is not applicable to a flexible substrate. Solution processes often involve low processing temperature and cheap precursor, can be used with flexible substrates, and offer the possibility of roll-to-roll manufacturing, potentially reducing manufacturing costs for the module. Here, we have experimentally investigated the optimum synthesis conditions for CIGSe nanoparticles fabricated by using a facile and a non-vacuum reflux method for low-temperature solution processes. By employing various reflux conditions by changing the temperature of heating mantle, single-phase CIGSe nanoparticles were synthesized at 200 °C. On the other hand, synthesized products with an impure multi-phase were formed at heating mantle temperatures lower than 200°C. XRD measurements confirmed that the Ga content of the CIGSe nanoparticles increased with increasing heating mantle temperature. In addition, the average diameter of the CIGSe nanoparticles increased with increasing reaction time from 5 min to 30 min at a fixed heating mantle temperature of a 200 °C. The optical band gap is calculated by using ultraviolet-visible (UV-Vis) absorption spectra, decreased from 1.69 eV to 1.29 eV with increasing reaction time due to the increased CIGSe nanoparticles size. From our results, we can conclude that the characteristics of the CIGSe nanoparticles can be effectively controlled by using simple growth conditions, thereby providing many advantages for the fabrication of absorber layers for use in CIGSe solar cells.
The fabrication conditions of the light absorber layer (organic-inorganic halide perovskite) have a very large effect on the device performance in perovskite solar cells. In case of using the 1-step ...anti-solvent treatment (AST), their show very different characteristics depending on the AST time, amount, and temperature, etc. Here, we determined the optimal AST time for the synthesis of perovskite light absorber layer in relation to the turbidity point (TP) of the precursor solution during spin coating according to the temperature inside the glovebox. The TP was examined according to the fluid flow of the host solvent, and it depended on various conditions, such as the temperature and substrate. The measured TP was almost identical to the estimated TP, and both tended to decrease as the internal temperature increased. The AST time and the internal temperature of the glovebox significantly affected the crystallinity and device performance of the perovskite, and the best device performance of 18.9% for a methylammonium lead iodide (MAPbI3) solar cell with n-i-p normal planar structure was achieved by applying an AST time of 9.5 s at 25 °C. Drive-level capacitance profiling and thermal admittance spectroscopy results confirmed that the optimal AST time of 9.5 s yielded a minimum trap density of 2.1 × 1015/cm3, which was related to the trap states of MAPbI3.
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•The investigation of optimal anti-solvent treatment time according to the temperature inside glove box for perovskite solar cells.•Analysis of defect density and state by drive level capacitance profile and admittance measurement for MAPbI3 based perovskite solar cells.•Investigation of MAPbI3 perovskite solar cells with n-i-p planar structure.•Study in relation to the Meyerhofer model, which is the fluid flow of the host solvent, and the antisolvent process for perovskite thin film layer.
In this article, we present a 4.13-GHz ultrahigh-speed (UHS) pseudo two-port SRAM for high-performance computing (HPC) in 4-nm FinFET technology. By applying the bitline (BL) charge time reduction ...(BLCTR) with clamped BL discharge (CBLD) scheme that improves BL charge and write time, the flying word-line (WL) architecture that enhances WL enable time, and the dual address pumping (DAP) architecture with flip-flop that reduces read and write switching time and address latching time, the proposed pseudo two-port SRAM demonstrates a UHS performance with a 4.13-GHz operating speed. A test-chip using the proposed scheme and architecture is fabricated in Samsung 4 nm FinFET technology and demonstrates UHS pseudo two-port 32-Kb SRAM operating at 4.13 GHz under 0.85 V and 100 c conditions.
Recent studies have demonstrated that copper (I) thiocyanate (CuSCN) has huge potential as a hole extraction material (HEM) for perovskite solar cells. Here, we used CuSCN as a HEM and analyzed its ...relationships with a methylammonium lead iodide (MAPbI
) perovskite layer. The CuSCN dissolved in diethyl sulfide (DES) was spin-coated on the MAPbI
layer. For high-quality and dense CuSCN layers, post-annealing was carried out at various temperatures and times. However, the unwanted dissociation of MAPbI
to PbI
was observed due to the post-annealing for a long time at elevated temperatures. In addition, DES, which is used as a CuSCN solvent, is a polar solvent that damages the surface of MAPbI
perovskites and causes poor interfacial properties between the perovskite layer and HEM. To solve this problem, the effect of the molar ratio of methylammonium iodide (MAI) and PbI
in the MAPbI
precursor solution was investigated. The excess MAI molar ratio in the MAPbI
precursor solution reduced MAPbI
surface damage despite using DES polar solvent for CuSCN solution. In addition, dissociation of MAPbI
to PbI
following an adequate post-annealing process was well suppressed. The excess MAI molar ratio in the MAPbI
precursor could be compensated for the MA loss and effectively suppress phase separation from MAPbI
to MAI + PbI
during post-annealing. The efficiency based on the normal planar structure of CuSCN/MAPbI
(using excess MAI)/TiO
was approximately 17%. The CuSCN-based MAPbI
device shows more optimized stability than the conventional spiro-OMeTAD under damp heat (85 °C and 85% relative humidity) conditions because of the robust inorganic HEM.
Providing performance-and-power optimized SRAM compiler with wide a range of operating voltages and configurations is a major challenge in advanced technologies. In this paper, the Row Auto-Tracking ...Write Assist (RATWA) and Voltage Auto-Tracking Pulse Generator (VATPG) are proposed to overcome major two issues in the SRAM compiler. The RATWA efficiently controls the strength of write assist under various types of SRAM RPB (Rows Per Bitline), and it demonstrates a 7% dynamic power improvement, especially at 64 RPB. The VATPG adaptively adjusts the gate level of the tracking circuit and shows a stable read margin across a wide range of voltages, up to 22% SRAM read speed improvement, and 9% dynamic power saving at higher voltage ranges.
Multiple‐cation perovskites have been extensively researched for stability enhancement, but limited literature exists on CsFAMA (CFM) solar cell stability under harsh temperature and humidity. This ...article focuses on the development of damp‐heat‐resistant CFM‐based perovskite solar cells (PSCs) through the implementation of various surface treatment strategies, including antisolvent treatment (AST) control and alkyl‐type interfacial passivation, while also proposing an effective encapsulation structure. The Cs+ ratio in Csx(FA0.91MA0.09)1−xPb(I,Br)3 perovskites is varied in the range of x = 0 to 0.362, and the AST times are explored by adjusting from 8 to 15 s. Remarkably, a power conversion efficiency (PCE) is achieved with significant improvements in open‐circuit voltage and fill factor at an AST time of 12 s. Through precise tuning of the Cs ratio to x = 0.17 (Cs0.17(FA0.91MA0.09)0.83Pb(I,Br)3) and introduction of an octyl‐ammonium iodide interlayer, the highest‐performing device with a PCE of 20.82% is obtained. Additionally, a low‐temperature vacuum lamination is employed, and the conducive tape in a twisted form is extended, which effectively seals the device. This results in superior stability for 500 h under damp‐heat conditions at 85 °C and 85% relative humidity. This encapsulation method holds significant promise as a potential solution for the modularization of PSCs.
The development of a damp‐heat‐stable multiple‐cation perovskite solar cell by applying various surface treatment strategies and an effective encapsulation structure is presented. The best‐performing device achieves 20.82% efficiency and shows superior stability for 500 h under conditions at 85 °C and 85% relative humidity. This shows great promise as a potential solution for the modularization of perovskite solar cells.
